Improvement in steam-gauge for heat and pressure



2 sheets-sheet 1;

J M. BLANCHARD. Steam,Heat and Pressure Gage. f

Patented July 13, 1869.

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Patented July '13, 1869.

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Letters Patent No. 92,572, dated July, 13, 1869.

IMPROVEMENT IN STEAM-GAUGE FOR HEAT AND PRESSURE.

"Ihe Schedule referred to in these Letters Patent and making part of the same.

To all whom it may concern:

Be it known that I, Janus M. Bnatrcrmun, of Washington, in the county of Washington, and District of Columbia, have invented a new and useful Improvement in Steam and Heat-Gauges, or Indicators and I do hereby, declare that the following is a full, clear, and exact description of the same, reference being had to the annexed drawings, making part of this specification, in which- Figure l is an elevation of a gauge, constructed in accordance with' my invention, showing a portion of the pipe through which the pressure is transmitted to 'the column of mercury.

Figure 2 is a sectional elevation of the same, showing the steam and air-chambers, and also the means of attaching the same to the generator, as well as for attaching the pipe to the gauge,

Figure 3 is an elevation, partly in section, of the gauge, with all of its parts in position, and at the same time showing how the glass portion of the indieating-tube may be protected by a tube of metal, which is made to surround the same.

Figure 4 is a sectional elevation of a portion of the iron pressure-tube, and of the glass portion of such tube, and the means of uniting the two, and of forming the joint between them.

Corresponding letters refer to corresponding parts in the several figures.

This invention relates to steam or pressure-gauges, or pressure-indicators and It consists in combining the following elements in such a manner'as to constitute a gauge, or indicator,

.for the purpose above indicated, viz: A steam-chamber, arranged outside of but communicating with the steam-space of the generator; a close chamber, containing air or other gaseous substance, which does not liquefy in cooling, placed within said chamber; and a bent pipe, of glass, or of metal and glass, containing mercury, or any suitable liquid to indicate the expan sion of the air or gas; and a scale to show the press ure.

A, in the drawings, represents a globular, or other suitably-formed vessel, which may be of cast-iron, brass, or any other suitable material, having upon its lower end a projection, upon which there is chased a screw-thread, for securing it into the generator or other vessel for containing steam, and upon its upper end a screw-thread, or other suitable device for attaching the nut, which secures thereto the pressure-pipe.

This vessel has formed within it two chambers, B and O, as shown in fig. 2 of the (hawings. These chambers have no communication, the- One with the other, but the chamber B communicates freely with the vessel containing the steam, which, when it enters said clmrnber, surrorn'rds the chamber (J, which contains air at the ordinary pressure of the atmosphere,

or it may be any expansible gas, which does not liqueiy 7 in becoming cooled, and which is heated,-by the steam in chamber B, to the temperature of such steam.

The chamber 0 communicates with the pipe which leads from the vessel A to the column or body of mercury, and is so connected therewith, that as the air or gas in said chamber becomes heated, and consequently expanded, its expansive force shall act upon such column or body of mercury, and cause it to rise in a tube ,or vessel, or, in any other convenient manner, indicate the pressure of the steam corresponding to any given temperature.

B and G are the chambers above referred to, their construction and arrangement being clearly shown in fig. 2 of the drawings.

D is a nut, which is made to embrace the pipe E, and seciu'e the same to the vessel A, by being screwed upon the thread formed thereon, as clearly shown in the drawings.

E is an iron or other pipe, capable of resisting the action of mercury, which has, upon that end thereof which is secured to the vessel A,- a flange, a, which, when suitably connected with said vessel, and pressed upon by the nut D, forms a tight joint between such flange and vessel, and prevents the possibility of the escape of any air or gas at that point.

This pipe is extended vertically for a distance suiiicient to permit the nut to be turned to its seat, when it is curved, as shown in fig. 3, and extends downward for a distance equalto the height to which it is desired to have the column of mercury rise in indicating the pressure of the steam;

At this point the pipe is bent upward, and extends a short distance, where it has joined to it a glass tube, by the means shown in figs. 3 and 4 of the drawings.

F is a tube, of glass or other transparent substance, which has an aperture through it, corresponding, .or nearly corresponding ip size ith the aperture in the pipe E, with which it connects.

This pipe or tube has formed uponits outer surface a collar or'flangc, as clearly shownin fi 4, which 001-' lar is for the pin-pose of being borne upon by the nut K, which secures it to the pipe E, the upper end of which is countersunk, or made concave, to receive the convex end of such tube, the object of this tube being to permit the mercury to rise therein, as it is pressed upon by the expanded air or gas, and'thus enable the attendant to determine the exact amount of pressure.

G is a packing, of some elastic material, such as rubber, gutta-percha, or paper, which is made tosurround the glass tube, when such a tube is used, for the purpose of protecting the same, it being held in its position by means of the covering H.

H is a covering of metal, which is madeto surround the tube E, and its enclosing elastic covering, with the exception of a space or spaces, 1), which are left open, for the purpose of rendering the position of t. 10 mercury visible, which is effected by having one slot on each side of the tube. This covering isto be slipped over the tube, and is desighed to protect the tube from injury; and it may also serve as the index-plate, upon which may be engraved the pressure in pounds of the steam, and the temperature due to such pressure, and thus cause the gauge to be an educational instrument, as well as an indicator of pressure.

I is the nut which secures the glass tube to the iron portion of the indicating-tube.

Some of the advantages which a gauge constructed as above described possesses over those of the usual construction, are-- 7 First, it is a perfect indicator of the pressure of the steam in the vessel with which it is coimected, owing to the fact that it can only indicate pressures which are due to certaintemperatures, and as the relations between these never change, there cannot be any. change in the result, however long the gauge may have been in use.

Secondly, there are no moving parts, to become worn or weakened by their own motion, neither are there any inaccuracies, to be multiplied by the diii'erence of the distance through which certain parts move, as compared with the distance through which certain other parts move, as in the case of spring or diaphragmgauges.

Third, it is a perfectsafety-gauge, because of the fact that the mercury-tube is open at the top, and consequently-any increase of the temperature of the steam, from any cause, above what is due to saturated steam, will act upon the air .or 'gas, to such an extent as to throw the mercury out of the tube or vessel, thus giving notice of the dangerous condition of the contents of the generator.

Fourth, its first cost, and consequently the price at which it can be sold to the public, is less than that of any gauge with which I am acquainted.

Firth, it is simple in construction and in its operation, it only requiring to be screwed into the generator,

or other vessel, or conduit, containing steam or other gaseous substance to be gauged, and then to have the indicating-pipe attached, and some suit-ablepacking placed between its flange and the projection upon the vessel on which it rests, when the nut is turned down until it is made tight, and then the transparent tube is to be attached by being suitably packed, and the nut I screwed down until a tight joint is made, when the instrument is ready for use. 1

If now, steam is admitted to the vessel, which may be done by means of a cook or valve placed in the projection on the lowe'nend of the vessel A, or it may be allowed to flow in, as it is generated, it will impart its heat to the contents ofthe vessel or chamber C, which contents will be expanded in a fixed and known relation to, the increasing temperature of the steam, and consequently will press upon the mercury in the tube or vessel, and cause it to rise a given dis tance for every given increase of tempenture of the steam; and as the relation between, temperature and pressure is governed by a fixed or natural law, it follows that an instrument constructed as above described, or any variation of the same, acting upon the same principle, will be at all times a perfect, or nearly perfect. indicator of the'pressure, as well as of the temperature of the steam surrounding the vessel or chamber 0. p

It is apparent that the form of the device shown may be varied to a great extent, without in any sense changing the nature or scope of the invention, and hence I do not desire to be understood as limiting myself to the device shown; but having thus fully described and shown one form of instrument for carrying out the principle of my invention,

What I'claim, and desire to seem-e by Letters Patent, is-- A steam gauge or pressure-indicator, combining in its construction the following elements, viz: A steamchamber, B, arranged outside of but connnunicating with the steam-space of the generator; a close chamber, G, containing air or other gaseous substance, which does not liquefy in cooling, placed within said chamber B; and a bent pipe, E F, of glass, or of metal and glass, containing mercury, or any suitable liquid, to indicate the expansion of the air or gas; and a scale, to show the pressure, substantially as set forth.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses \Vitnesses: JAMES M. BIL-\NQHARD;

D. 1. HoLLowAr, Anni. B. Wnrrn. 

